This invention generally relates to cardiovascular procedures such as angioplasty, angiography and valvuloplasty, and more particularly to the connection of guidewire extensions for use in such procedures.
Guidewires are currently used to facilitate the placement of catheters in the arterial system of a patient for cardiovascular procedures. The guidewire is typically on the order of 20-50 cm longer than the catheter to permit the guidewire and the catheter to be advanced relative to each other as they are steered into position within the patient's body. Suitable guidewires are described in U.S. Pat. Nos. 4,538,622 (Samson et al.); 4,554,929 (Samson); and 4,569,347 (Frisbie) which are hereby incorporated herein in their entirety.
In a typical procedure to change catheters, the guidewire is removed from the patient, and an exchange wire is inserted in its place. The in-place catheter is removed from the patient and a new catheter is inserted into the patient over the exchange wire. The exchange wire is then removed from the patient and the guidewire is reinserted. The exchange wire is substantially longer than the guidewire, and it generally extends outside the patient's body for a distance greater than the length of the catheter to facilitate the catheter exchange. With a dilation catheter having a length on the order of 120-140 cm, for example, a guidewire might have a length on the order of 175 cm, and an exchange wire might have a length on the order of 300 cm. The use of an exchange wire has the obvious disadvantage that it complicates the angioplasty procedure.
Copending application Ser. No. 137,963, now Pat. No. 4,827,941 filed Dec. 23, 1987, by Taylor et al. and assigned to the present assignee described means to eliminate the need for an exchange wire by attaching an extension wire to an in-place guidewire to extend the length thereof whenever a catheter is to be exchanged. As described herein, the two wires are joined together by a female tubular element on the end of one of the sections and a male element on the end of the other section which is releasably secured within the tubular element. The aforesaid copending application is hereby incorporated herein in its entirety.
While an improved guidewire system is described in the aforesaid copending application, the tubular element and the male interfitting element of the guidewire and extension have very small diameters which makes the manual insertion of the interfitting element into the tubular element very difficult, particularly in the conditions in which the cardiovascular procedures are conducted.